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spring+springdatajpa+freemarker

2013-03-08 11:14 507 查看

最近需要使用springMVC 使用 spring data jpa作为dao层。以前没有接触过。赶紧学学。记录一下。

spring data 帮我们封装了很多dao层实现。让我们只需要定义接口就可以直接使用很多基本的查询。

自己从0开始建项目熟悉一下框架的搭建。使用的 eclipse for javaee 。使用 maven管理。

首先建立一个maven项目。

添加 web.xml 作为 web应用的核心配置。这个可不能少。

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<display-name>test2</display-name>
<!-- 编码过滤。 使用 utf-8编码 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- spring的核心控制器配置。 -->
<servlet>
<servlet-name>spring-servlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置文件的位置。默认 好像是 ApplicationContext.xml？ 不太确定 太久不用默认的了 反正我都是自己配置一个新的 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-servlet-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring-servlet</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>

建立 spring-servlet-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd"> <!--配置文件 -->
<context:property-placeholder location="classpath:config.properties"/>

<context:annotation-config />
<mvc:annotation-driven />
<!-- 扫描这个包下面的注解，自动注入bean -->
<context:component-scan base-package="com.aurora.test2" />
<!-- 将配置文件分开 便于管理 -->
<import resource="spring-mvc.xml"/>
<import resource="spring-orm.xml"/>
</beans>

spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> 
<bean id="viewResolver"
class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
<property name="cache" value="true" />
<property name="prefix" value="" />
<property name="suffix" value=".ftl" />
<property name="contentType" value="text/html;charset=UTF-8"></property>
<property name="requestContextAttribute" value="request" />
<property name="exposeSpringMacroHelpers" value="true" />
<property name="exposeRequestAttributes" value="true" />
<property name="exposeSessionAttributes" value="true" />
</bean>
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="1000000"/>
</bean>

<bean id="freemarkerConfiguration" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="location" value="classpath:freemarker.properties"/>
</bean>

<bean id="freemarkerConfig"
class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
<property name="templateLoaderPath" value="/WEB-INF/view/" />
<property name="freemarkerSettings" ref="freemarkerConfiguration"/>
</bean>
<mvc:default-servlet-handler/>
<mvc:resources location="/images/**" mapping="/images/"/>
<mvc:resources location="/uploads/**" mapping="/uploads/"/>
</beans>

spring-orm.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd" >

<bean
id="dataSource"
class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close"
init-method="init" >

<property
name="url"
value="${jdbc.url}" />

<property
name="username"
value="${jdbc.user}" />

<property
name="password"
value="${jdbc.password}" />

<property
name="filters"
value="stat" />

<property
name="maxActive"
value="20" />

<property
name="initialSize"
value="1" />

<property
name="maxWait"
value="60000" />

<property
name="minIdle"
value="1" />

<property
name="timeBetweenEvictionRunsMillis"
value="3000" />

<property
name="minEvictableIdleTimeMillis"
value="300000" />

<property
name="validationQuery"
value="SELECT 'x'" />

<property
name="testWhileIdle"
value="true" />

<property
name="testOnBorrow"
value="false" />

<property
name="testOnReturn"
value="false" />

<property
name="poolPreparedStatements"
value="true" />

<property
name="maxPoolPreparedStatementPerConnectionSize"
value="20" />
</bean>

<!-- entity manager config -->

<bean
id="emf"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
p:dataSource-ref="dataSource" />

<!-- transaction manager config -->

<bean
id="txManager"
class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="emf" />

<tx:annotation-driven transaction-manager="txManager" />

<jpa:repositories
base-package="com.aurora.test2.dao"
entity-manager-factory-ref="emf"
transaction-manager-ref="txManager" />

</beans>

config.properties

#jdbc
jdbc.url=jdbc:oracle:thin:@xxx.xxx.xxx.xxx:1521:xxxx
jdbc.user=xxx
jdbc.password=xxx

freemarker.properties

tag_syntax=auto_detect
template_update_delay=2
default_encoding=UTF-8
output_encoding=UTF-8
locale=zh_CN
date_format=yyyy-MM-dd
time_format=HH:mm:ss
datetime_format=yyyy-MM-dd HH:mm:ss

hibernate.properties

hibernate.show_sql=true
hibernate.format_sql=true

还需要在 resources/META-INF/ 下面配置 persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation=" http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">

<persistence-unit name="xiaoyu" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
</persistence-unit>
</persistence>

需要在 pom.xml 里面添加依赖包

<dependencies>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.0.9</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jms</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>3.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.3.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.1.9.Final</version>
</dependency>
<dependency>
<groupId>org.freemarker</groupId>
<artifactId>freemarker</artifactId>
<version>2.3.19</version>
</dependency>
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>0.2.11</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.23</version>
</dependency>
</dependencies>

还需要注意一点之前我们配置freemarker的根目录

<bean id="freemarkerConfig"
class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
<property name="templateLoaderPath" value="/WEB-INF/view/" />
<property name="freemarkerSettings" ref="freemarkerConfiguration"/>
</bean>

所以必须要在 /web-inf/ 目录下建立 view文件夹。

ok 运行一下项目启动了。环境就搭好了。

下面开始添加java代码注意刚刚配置了注解注入的包路径是

<context:component-scan base-package="com.aurora.test2" />

所以我们的java代码的包路径必须是这个。

在该包下建立 mvc看框架. controller 包. dao包 entity 包 service包

controller

package com.aurora.test.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping(value="/test")  //控制器map
public class TestController {

//@Autowired
//private FeedbackService feedbackService;  //注入 服务

@RequestMapping(value="/list") //请求map
public ModelAndView list() {
ModelAndView mv = new ModelAndView();
mv.setViewName("test_list");
//mv.addObject("count", feedbackService.count());
//mv.addObject("system",feedbackService.systemFeedback());
//mv.addObject("named",feedbackService.testNamed());
return mv;
}

@RequestMapping(value="/list/{id}")
public ModelAndView userList(@PathVariable Long id) {
ModelAndView mv = new ModelAndView();
mv.setViewName("user_list");
//mv.addObject("feedbacks", feedbackService.userFeedbacks(id));
return mv;
}
}

service层

FeedbackService.java

package com.aurora.test.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.aurora.test.dao.FeedbackRepository;
import com.aurora.test.dao.UserRepository;
import com.aurora.test.entity.Feedback;
import com.aurora.test.entity.User;

@Service
@Transactional
public class FeedbackService {
@Autowired
private FeedbackRepository feedbackRepository;
@Autowired
private UserRepository userRepository;

public long count() {
return feedbackRepository.count();
}

public Feedback systemFeedback() {
return feedbackRepository.systemFeedback();
}

public List<Feedback> userFeedbacks(Long userId) {
User user = userRepository.findOne(userId);
return feedbackRepository.findByUser(user);
}

public Feedback testNamed() {
return feedbackRepository.testNamed();
}
}

entity 建立了2个简单的单表映射就不写了。

主要是dao层。 spring data 是只需要写接口就可以了。

一个简单的例子

package com.aurora.test2.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import com.aurora.test2.entity.User;

public interface UserRepository extends JpaRepository<User, Long> {

}

这样就可以了可以使用默认的很多方法。绝大部分这就已经足够了。基本的增删查改甚至分页什么的都可以了。但是也许你需要一些特殊的查询。比较复杂需要些sql。你可以这样

@Query("from Feedback f where f.user.id=?1")
public List<Feedback> listCunstom(Long userId);

一些参数可以这样

public interface UserRepository extends JpaRepository<User, Long> {

@Query("select u from User u where u.firstname = :firstname or u.lastname = :lastname")
User findByLastnameOrFirstname(@Param("lastname") String lastname,
@Param("firstname") String firstname);
}

通过注解的 query 来写 hql语句就可以了。
还可以通过查询的方法名来实现一些查询。比如

findByUser(User user)

定义这个方法就可以了不用实现。spring data会自动帮你实现。只要你满足特定的格式。下面是一些关键字


Keyword	Sample	JPQL snippet
And	findByLastnameAndFirstname	… where x.lastname = ?1 and x.firstname = ?2
Or	findByLastnameOrFirstname	… where x.lastname = ?1 or x.firstname = ?2
Between	findByStartDateBetween	… where x.startDate between 1? and ?2
LessThan	findByAgeLessThan	… where x.age < ?1
GreaterThan	findByAgeGreaterThan	… where x.age > ?1
After	findByStartDateAfter	… where x.startDate > ?1
Before	findByStartDateBefore	… where x.startDate < ?1
IsNull	findByAgeIsNull	… where x.age is null
IsNotNull,NotNull	findByAge(Is)NotNull	… where x.age not null
Like	findByFirstnameLike	… where x.firstname like ?1
NotLike	findByFirstnameNotLike	… where x.firstname not like ?1
StartingWith	findByFirstnameStartingWith	… where x.firstname like ?1 (parameter bound with appended % )
EndingWith	findByFirstnameEndingWith	… where x.firstname like ?1 (parameter bound with prepended % )
Containing	findByFirstnameContaining	… where x.firstname like ?1 (parameter bound wrapped in % )
OrderBy	findByAgeOrderByLastnameDesc	… where x.age = ?1 order by x.lastname desc
Not	findByLastnameNot	… where x.lastname <> ?1
In	findByAgeIn(Collection<Age> ages)	… where x.age in ?1
NotIn	findByAgeNotIn(Collection<Age> age)	… where x.age not in ?1
True	findByActiveTrue()	… where x.active = true
False	findByActiveFalse()	… where x.active = false

还有另外一种我不是很喜欢用通过

@NamedQuery 来这个跟以前的一样。就是在entity上面使用 @NamedQuery 定义语句。然后在借口里面也定义这个方法就可以了。

官方例子

@Entity
@NamedQuery(name = "User.findByEmailAddress",
query = "select u from User u where u.emailAddress = ?1")
public class User {

}

dao层

public interface UserRepository extends JpaRepository<User, Long> {

List<User> findByLastname(String lastname);

User findByEmailAddress(String emailAddress);
}

如果这些都不能满足你的需求（一般情况肯定够用了）

想要不适用 springdata 的就用原来的 jpa 就需要这样了。

像普通的 dao 层一样定义一个接口 FeedbackDao.java 实现类 FeedbackRepositoryImpl.java

然后在定义一个接口 UserRepository.java extends JpaRepository<Feedback, Long>,FeedbackDao

我们使用 UserRepository接口就可以使用自定义的方法和自动实现的方法。很方便。

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